Polythiophene compositions for improving organic light-emitting diodes

Abstract

The invention relates to compositions which include: (a) a polythiophene containing repeating units represented by the following general formula (I), wherein X represents, for example, —CH 2 —CH(CH 2 —O—(CH 2 ) 4 SO 3 − H + )—; and (b) further polymers, that are different than polythiophene (a), and which contain SO 3 − M + or COO − M + groups. Also disclosed are electroluminescing (EL) arrangements that contain hole-injecting layers which include such compositions.

1 . A composition comprising: 
 (a) at least one polythiophene containing repeating units of the general formula (I)                        wherein,    X denotes —(CH 2 ) x —CR 1 R 2 —(CH 2 ) y —, wherein 
 R 1  denotes a member selected from the group consisting of —(CH 2 ) s —O—(CH 2 ) p —R 3  and —(CH 2 ) q —O—(CH 2 CH 2 O) r R 4 , where 
 R 3  denotes SO 3   − M +  or COO − M + ,  
  where M +  denotes H + , Li + , Na + , K + , Rb + , Cs +  or NH 4   + ,  
 s is an integer from 0 to 10,  
 p is an integer from 1 to 18,  
 R 4  denotes C 1 -C 4 -alkyl,  
 q denotes an integer from 0 to 10, and  
 r denotes an integer from 1 to 12,  
 
 R 2  independently of R 1  denotes a member selected from the group consisting of H, a linear or branched C 1 -C 20 -alkyl radical, a C 6 -C 14 -aryl radical, 
 —(CH 2 ) s —O—(CH 2 ) p R 3  and —(CH 2 ) q —O(CH 2 CH 2 O) r R 4 ,  
  where R 3 , s, p, R 4 , q and r have the meanings given for R 1 ,  
 and  
 
 x, y each independently denote an integer from 0 to 9, and  
     (b) at least one further polymer, that is different that said polythiophene (a), having a moiety selected from the group consisting of SO 3   − M +  groups and COO − M +  groups, in which M +  in each case denotes a member selected independently from the group consisting of H + , Li + , Na + , K + , Rb + , Cs +  and NH 4   + .    
     
     
         2 . The composition of  claim 1  wherein, 
 M +  in each case denotes a member selected independently from the group consisting of H + , Na +  and K + ,    s is an integer from 0 to 3,    p is an integer from 2 to 6, and    x, y in each case independently denote an integer from 0 to 3.    
     
     
         3 . The composition of  claim 1  wherein, 
 M +  denotes H + ,    s denotes 0 or 1,    p denotes 3, 4 or 5, and    x, y in each case independently denote 0, 1 or 2.    
     
     
         4 . The composition of  claim 1  wherein R 2  denotes H.  
     
     
         5 . The composition of  claim 1  wherein said further polymer (b) is selected from the group consisting of a polymeric carboxylic acid, a polymeric sulfonic acid, a partially fluorinated polymer containing sulfonic acid groups, and a perfluorinated polymer containing sulfonic acid groups, and their respective salts.  
     
     
         6 . The composition of  claim 1  wherein said further polymer (b) is selected from the group consisting of polystyrenesulfonic acid, and a copolymer of tetrafluoroethylene and of the fluorovinylether of poly(hexafluoro propylene oxide)mono(tetrafluoro vinyl sulfonic acid)ethers and their respective salts.  
     
     
         7 . The composition of  claim 1  wherein said composition comprises at least two further polymers (b).  
     
     
         8 . The composition of  claim 7  wherein said two polymers are polystyrene sulfonic acid and a copolymer of tetrafluoroethylene and of the fluorovinylether of poly(hexafluoro propylene oxide)mono(tetrafluoro vinyl sulfonic acid)ethers and their respective salts.  
     
     
         9 . The composition of  claim 1  wherein said composition has a weight ratio of said polythiophene (a) to said further polymer (b) of 1:2 to 1:15.  
     
     
         10 . The composition of  claim 1  further comprising at least one polar diluent.  
     
     
         11 . The composition of  claim 10  wherein said polar diluent is selected from the group consisting of water, alcohols and mixtures thereof.  
     
     
         12 . The composition of  claim 10  wherein said polar diluent is selected from the group consisting of water, methanol, ethanol, n-propanol, 2-propanol, n-butanol and mixtures thereof.  
     
     
         13 . An article of manufacture selected from the group consisting of hole-injecting layers in EL arrangements, hole-transporting layers in EL arrangements, organic solar cells, organic laser diodes, organic thin-film transistors, organic field-effect transistors, electrodes and electrically conducting coatings, wherein said article comprises the composition of  claim 1 .  
     
     
         14 . An electroluminesing arrangement comprising: 
 a substrate,    at least two electrode layers,    at least one an emitter layer, and    at least one hole-injecting layer,    wherein,    at least one electrode layer abuts said substrate,    said emitter layer is interposed between two electrode layers, and    at least one hole-injecting layer is interposed between one of said electrode layers and said emitter layer, and    further wherein,    said hole-injecting layer comprises the composition of  claim 1 .    
     
     
         15 . Organic light emitting diode comprising an EL arrangement according to  claim 14.